Process and apparatus for producing filled dough products

Abstract: A process for the production of filled dough products in which dough and a filling are co-extruding to provide a filled tube of the dough surrounding the filling. The filled tube is then transported on a movable support. While being transported, the filled tube is cut into segments using a plurality of blades which move with the filled tube and which progressively cut into the filled tube with progressive movement of the filled tube so that filling in the portion of the tube to be cut is progressively pushed out of this portion prior to cutting when the blade engages the moving support. The invention also relates to an apparatus for carrying out the process.

Description: This invention relates to a process for the production of food products that have a dough coating containing a filling. The invention also relates to apparatus for producing the filled dough products. The production of filled dough products on a continuous basis is difficult. One conventional way of producing these products is to produce two sheets of dough and then place discrete portions or a layer of filling on one of the sheets. The other sheet is then placed over the first and the laminated dough is cut into rectangles or squares. Particularly the cutting of the sheets is done by hand or by stepwise operation; both slow processes. Also scraps of dough are invariably produced, leading to wastage. A procedure for automating this process is described in US patent 4941402. Here one sheet of dough is transported on a conveyor to a filling station at which streams of filling are placed on the sheet; the streams being arranged in parallel along the length of the sheet. The coated sheet is then transported to a rotating cylinder in a manner such that the coated sheet moves over the cylinder and downwardly with the rotation of the cylinder. The other dough sheet is rotated through 180° on a pocket forming cylinder, by means of which small pockets are pressed into the sheet. The pocketed sheet is then pressed onto the coated sheet with the pockets receiving the filling on the coated sheet. A cutting roller then cuts the sheets between the pockets. A problem with this process is that not all the filling is pushed from between the sheets at the joins of the pockets. Hence improper sealing of the pockets can occur, as well as sticking of the sheets to the cylinders and rollers. Also the dough must have sufficient strength to be able to be worked over a number of cooperating rollers. Not all doughs have this strength. Alternatively, the food product can be produced in the form of an extruded rope. This is done by co-extruding the dough and the filling with the dough arranged concentrically around the filling. An apparatus to produce food products in this manner is described in European patent application 0162675. Here the extruded rope is first pinched into segments using a pair of cooperating rollers, and then the segments are separated using arcuate cutters decending from above. Again however, some filling may remain in the areas to be cut resulting in improper sealing and sticking. European patent application 0172051 discloses a process for producing filled dough products. A filled dough is fed into a rotating cutting apparatus in which the filled dough is segmented by blades (33, 34) fixed to a pair of endless conveyors. It is therefore an object of this invention to provide a process for the continuous production of filled dough products which is simple and which has a low degree of improper sealing of the dough. It is also an object to provide an apparatus for use in the process. Accordingly, in one aspect this invention provides a process for the production of filled dough products comprising co-extruding dough and a filling to provide a filled tube of the dough surrounding the filling, and cutting the filled tube into segments; characterised by: transporting the filled tube on a movable support through a cutting station having a plurality of movable blades spaced from one another a distance corresponding to a selected length of the segments; causing a surface of each segment of the filled tube opposite the movable blades to progressively take on a convex shape with progressive movement of the filled tube; and progressively cutting the filled tube into segments by causing the plurality of blades to move with the filled tube and progressively towards the movable support at an angle of about 2 to 30° and into the filled tube with movement of the filled tube through the cutting station, whereby the filling in any portion of the tube engaged by a blade is progressively pushed out of this portion prior to cutting when the blade engages the moving support. The invention therefore has the advantage that the blade slowly stretches the dough at the portion of the filled tube to be cut with progressive movement of the filled tube and this causes the filling in this portion to be pushed out of this portion. In tests done using the process, almost no improper sealing and sticking is observed; even at speeds of 200 cuts per minute. Also the process is continuous and hence does not require inefficient stepwise operations. Further, there is no wastage. To improve the handling properties of the filled tube, the filled tube may be coated with ultra fine semolina prior to being cut. In a further aspect, this invention provides a cutting apparatus for continuously cutting dough strands, the apparatus comprising: an endless support conveyor to transport the dough strand; and an endless cutting conveyor positioned above the support conveyor and carrying a plurality of blades spaced from each other along the length of the cutting conveyor, the distance between adjacent blades being equal to the desired length of the segments, and the cutting conveyor being inclined downwardly in the direction of transport of the support conveyor so that each blade moves downwardly towards the support conveyor with progressive movement along the cutting conveyor to finally engage the support conveyor and cut the dough strand. The apparatus is advantageously simple and its use results in little or no manipulation of the dough; enabling a wide range of doughs to be processed. Also it is capable of operating at high speeds yet maintaining good sealing of the dough when the filled tube is cut into segments. Hence the apparatus is a significant improvement over the art. The cutting apparatus is particularly useful for cutting filed tubes of dough; although it may be used to cut any stranded dough product. Preferably the cutting conveyor is inclined downwardly at an angle in the range of 2 to 30° to the support conveyor. More preferably, the angle is in the range of 5 to 20°, for example about 10°. Preferably, the support conveyor carries a plurality of raised support plates spaced from each other along the length of the support conveyor; the distance between the centre of one support plate and the centre of an adjacent support plate being substantially equal to the desired length of the segments. Even more preferably, each support plate is raised at its centre and slopes concavely away to its leading and trailing edges. The support plates may be in the form of elongate bars which extend transverse the support conveyor. In this way, a plurality of filled tubes may be loaded on the support conveyor and transported in parallel through cutting apparatus. Similarly, the blades may each comprise an elongate bar which extends transverse of the cutting conveyor; the bar having a raised cutting edge extending along its length. Preferably, the cutting edge has a shoulder portion at its base. Preferably the support conveyor and the cutting conveyor are each made up of a plurality of chains arranged in parallel; the support plates and the and blades being affixed to and extending across the chains. It will be appreciated that the invention may be used to produce a wide range of food products. One example of a food product is a savoury snack comprising a dough casing containing a savoury filling. After cutting, the snack may be deep fried and then frozen; the user heating up the snack in a microwave or conventional oven. Other examples are filled pasta products, products containing a sweet filling and the like. It will also be appreciated that the cutting apparatus can be used to cut unfilled dough products. An embodiment of the invention is now described, by way of example only, with reference to the drawings in which: Figure 1 is a cross-section of the cutting apparatus; Figure 2 is a cross section along line A-A in Figure 1; Figure 3 is a part-cross section perspective of a support plate; Figure 4 is a part-cross section perspective of a cutting plate; and Figure 5 is a cross-section of an extrusion nozzle. The cutting apparatus 2 consists of two endless conveyors; a support conveyor 4 and a cutting conveyor 6 arranged above the support conveyor 4. The support conveyor 4 consists of three endless chains 8 each strung about two return pulleys 10; one return pulley 10 at each end of the support conveyor 4. The return pulleys 10 are arranged such the support conveyor 4 extends substantially horizontally; although suitable inclinations to the horizontal are also acceptable. The endless chains 8 are spaced from one another and arranged in parallel with the axes of the return pulleys 10 at each end of the support conveyor 4 being connected. A plurality of cutting support plates 20 are connected to and extend transverse the endless chains 8, spaced from one another an equal distance along the chains 8. As is best illustrated in figures 2 and 3, each cutting support plate 20 is in the form of an elongate bar which is of length at least equal to the distance between the chains 8 at the sides of the support conveyor 4. A raised support 22 extends along the centre of the support plate 20 and is connected to the leading edge 24 of the support plate 20 by a concave leading surface 26. A concave trailing surface 28 extends from the opposite edge of the raised support 22 to the trailing edge 30 of the support plate 20. The distance from the centre of the raised support 22 of one support plate 20 to the centre of the raised support 22 of an adjacent support plate 20 is substantially equal to the desired length of the food product. A plurality of screw bores 32 (only one is shown) are provided in the back surface 34 of the support plate 20 along the centre-line of the support plate 20. A bolt (not shown) may be threaded in the screw bore 32 to affix the support plate 20 to the endless chains 8. The support plate 20 is made of stainless steel (for example AISI 304L) or any other suitable material. The cutting conveyor 6 consists of three endless chains 12 each strung about two return pulleys; an upstream return pulley 14 at one end and downstream return pulley 16 at the opposite end of the cutting conveyor 6. The cutting conveyor 6 also has a force pulley 18 positioned between the upstream return pulley 14 and the downstream return pulley 16. The upstream return pulleys 14 are positioned slightly above the downstream return pulleys 16 so that the chains 12 each extend downwardly from the upstream return pulleys 14 to the downstream return pulleys 16. The force pulleys 18 are positioned near the downstream return pulleys 16 and a little beneath the downstream return pulleys 16. In this way, the portion of each endless chain 12 beneath the return pulleys has a longer portion 36 inclining downwardly from the upstream return pulley 14 to the force pulley 18 and a shorter portion 38 inclining upwardly from the force pulley 18 to the downstream return pulley 16. The longer portion 36 inclines downwardly at a shallow angle of about 5 to 20% with respect to the support conveyor 4 beneath it. The endless chains 12 are spaced from one another and arranged in parallel with the axes of the upstream return pulleys 14 connected, the axes of the downstream return pulleys 16 connected and the axes of the force pulleys 20 connected. A plurality of cutters 40 are connected to and extend transverse the endless chains 12; spaced from one another an equal distance along the chains 12. As is best illustrated in figures 2 and 4, each cutter 40 is in the form of an elongate bar which is of length at least equal to the distance between the chains 8 at the sides of the support conveyor 4. A ridge 42 extends along the centreline of each cutter 40 and in turn has a recess 44 extending along its centreline. An elongate cutting blade 46 is fixed in the recess 44. The cutting blade 46 terminates in a sharp cutting edge 48 which projects well clear of the ridge 42. A serrated shoulder 50 is formed into the ridge 42 on each side of the cutting blade 46. The opposing faces of any serration of the serrated shoulders 50 face one another at angle of about 120°. A plurality of screw bores 52 (only one is shown) are provided in the back surface 54 of the cutter 40 along the centre-line of the cutter 40. A bolt (not shown) may be threaded in the screw bore 52 to affix the cutter 40 to the endless chains 12. The cutter 40 is made of plastics such as polyethylene or any other suitable non-stick material. The cutting blade 46 is made of stainless steel, for example AISI 304L, or any other suitable material. The distance between the blades 46 of each pair of adjacent cutters 40 on any chain 12 is equal to a desired length of food product. Also, the chains 8 and 12 are synchronized so that, when any cutter 40 reaches a position beneath the force pulley 18, a cutting support plate 20 is positioned beneath the cutter 40. Clearly, if the chains 8 are the same length as the chains 12, the number of cutters 40 on each chain 12 should be equal to the number of cutting support plates 20 on the corresponding chain 8. The force pulley 18 is positioned a distance above the support conveyor 4 such that the cutting edge 48 of the blade 46 of the cutter 40 directly beneath the force pulley 18 contacts the raised support 22 of the cutting support plate 20 beneath the force pulley 18. In this way, a cutting mechanism is provided. The chains 8 and 12 are driven by servo motors (not shown) which enable rapid and accurate adjustment of the speed of the chains 8 and 12 such that synchronization of the chains 8 and 12 may be ensured. The servo motors may be connected to suitable process control systems (not shown) to monitor and correct the speeds of the chains 8 and 12. Referring now to figure 5, a nozzle 50 for co-extruding a food product in the form of a filled tube is formed of an outer tube 52 which is bent in the form of an elbow to define an inlet portion 60 and an outlet portion 62. The outer tube 52 is of substantially constant diameter over its length but terminates in an outlet nozzle 54 of reduced diameter at the end of the outlet portion 62. An inwardly tapering intermediate portion 56 connects the outlet nozzle 54 to the remainder of the outer tube 52. An inner tube 58 extends along the axis of the outlet portion 62, from the outlet nozzle 54 rearwardly and out through the bend of the outer tube 52. The inner tube 58 is of constant diameter which is less than the diameter of the outlet nozzle 54. The join of the inner tube 58 and the outer tube 52 at the bend is sealed. A connecting pipe 64 projects from the bend of the outer tube 52, about the portion of the inner tube 58 external of the outer tube 52 and concentric with it. A suitable connector 66 is fixed to the distal end of the connector pipe 64 and the inner tube 58 so that a feed pipe 68 may be connected to the inner tube 58. A similar connector (not shown) is connected to the free end of the inlet portion 60 of the outer tube 52. An adjustment screw 70 is threaded through a fitting 72 fixed adjacent the intermediate portion 56 of the outer tube 52 to project into the outer tube 52. The distal end of the adjustment screw 70 abuts the inner tube 58. Hence, adjustment of the adjustment screw 70 causes adjustment of the position of the inner tube 58 in the outlet nozzle 54. A further adjustment screw (not shown) may be positioned to extend at right angles to the adjustment screw 70 to together provide for vertical and horizontal adjustment of the inner tube 58. In use, several nozzles 50, aligned in parallel, are positioned downstream of the cutting apparatus 2. A food filling is pumped into the inner tube 58 and a dough is pumped into the outer tube 52. This causes the dough to be extruded from the outlet nozzle 54 of each nozzle 50, about the food filling, in the form of a filled tube 80. The filled tube 80 is deposited on the support conveyor 4 where it is carried by the support plates 20. As the filled tube 80 is conveyed along the support conveyor 4, due to its elasticity, it progressively sags between adjacent support plates 20. This sagging continues until, once the filled tube 80 reaches the downstream end of the support conveyor 4, the lower surface of the filled tube 80 rest on the concave leading and trailing surfaces 26 and 28 of the support plates 20. In this way, the filled tube 80 is made up of connected segments 82 each having a lengthwise arcuate lower surface. This procedure causes some stretching and narrowing of the filled tube 80 at the joins 84 between adjacent segments 82, in turn tending to force the filling in the join 84 to flow into the adjacent segments 82. While this is proceeding, the cutting conveyor 6 is also moving (counter-clockwise in the apparatus illustrated in the drawings while the support conveyor moves clockwise). Due to the slight downward angle of inclination of the longer portion 36 of the cutting conveyor 6, the cutters 40 move downwardly as they move along the cutting conveyor 6. Once any cutter reaches some selected point intermediate the length of the cutting conveyor 6, the cutting blade 46 of the cutter 40 engages the filled tube 80 at a join 84 between two segments 82. Further movement of the cutter 40 along the cutting conveyor 6 causes the blade 46 to bite deeper into the join 84 of the filed tube 80. However, since the longer portion 36 of the cutting conveyor 6 is inclined at a shallow angle, the progressive biting of the blade 46 into the join 84 occurs slowly and progressively. Hence, a slow stretching of the join 84 occurs as well as a slow pushing out of the filling from the join 84 into the adjacent segments 82. Once any join 84 reaches a position beneath the force pulley 18, very little if any filling remains in the join 84. At this point, the cutting edge 48 of the cutting blade 46 cuts completely through the join 84 by cuttingly engaging the raised support 22 of the support plate 20 beneath the cutter 40. Shortly after the force pulley 18, the support conveyor 4 returns permitting the cut segments 82 to fall onto further transport means or unit process means (not shown) for further processing. Example 100 parts by weight of ordinary wheat flour, 20 parts by weight powdered lactoserum (pH 6.2), 3 parts by weight baking powder and 5 parts by weight egg powder are mixed in an Artofex kneading machine for 2 to 3 minutes. Between 25 to 30% by weight cold water at 15 to 16°C is then added to the kneading machine and the machine operated at speed II for 5 to 7 minutes. Once removed from the kneading machine, the dough is very supple and is used within the hour. A filling is then prepared by adding precooked meat, that has been chopped into 3 mm pieces, to a selected sauce. The sauce is then cooked. The filling is then cooled to less than 4°C. The dough is then fed into a Handtmann screw extruder of capacity between 50 to 500 kg/h from where it is transported to a distributor which divides the dough into six streams. The filling is fed into a MIM screw pump of 25 to 250 kg/hour capacity from where it is pumped to a distributor which divides the filling into six streams. Each stream of dough and filling is fed to a nozzle 50. Six nozzles 50 are arranged after the distributors. Each nozzle 50 has an outer tube 52 of diameter of 38 mm and an inner tube 58 of inner diameter of 6 mm and outer diameter of 8 mm. The outlet nozzle 54 of each nozzle 50 has an inner diameter of 11.7. The dough is pushed from the dough distributor into the outer tube 52 of each nozzle 50 and the filling is pumped from the filling distributor into the inner tube 58 of each nozzle 50. The six filled tubes 80 leaving the nozzles are then dusted with ultra fine semolina and conveyed to a cutting apparatus 2. The support conveyor 4 of the cutting apparatus 2 has three chains 8 arranged in parallel and spaced from each other (centre to centre) by about 165 mm. The chains 8 are made up of links of 9.52 mm. Each support plate 20 is 600 mm long and has a maximum thickness of about 5 mm. The cutting conveyor 4 of the cutting apparatus 2 has three chains 12 arranged in parallel and spaced from each other (centre to centre) by about 165 mm. The chains 12 are made up of links of 9.52 mm. Each cutter 40 is 600 mm long and has a maximum thickness at the cutting edge 48 of about 13 mm. The cutters 40 are spaced from adjacent cutters 40 along the chain by 38.08 mm. The cutting apparatus 2 is operated at a speed of 500 m/h. Each stream of filled tube 80 is transported along the cutting apparatus 2 and then cut into segments 82 of about 38 mm. No losses due to sticking or improperly cut filled tubes 82 are observed. The segments 82 fall into a deep frying apparatus where they are deep fried. Thereafter the fried segments are cooled, bagged and frozen. It is to be understood that the invention is not limited to the embodiment described and that numerous variations and modifications may be made. For example, more or less than three chains may be used for each of the support conveyor 4 and the cutting conveyor 6. Also, chains need not be used at all; particularly for the support conveyor 4. Instead conveyor belts may be used. It is also not necessary to have a single force pulley 18 for each chain 12, several force pulleys 18 may be used to provide for longer action cutting. Further, the force pulley 18 need not be positioned below the downstream return pulley 16; instead its lower surface may be at the same level as the lower surface of the downstream return pulley 16. In this case, the shorter portion 38 of each chain 12 will not be inclined upwardly. It is also possible to dispense with the force pulleys 18 entirely; in this case the downstream return pulleys 16 would perform the function of the force pulleys 18. Also, the leading and trailing surfaces 26 and 28 of the support plate 20 need not be concave; instead they may taper down to the edges of the support plate 20.

Claims: A process for the production of filled dough products comprising coextruding dough and a filling to provide a filled tube of the dough surrounding the filling, and cutting the filled tube into segments; characterised by: transporting the filled tube on a movable support through a cutting station having a plurality of movable blades spaced from one another a distance corresponding to a selected length of the segments; causing a surface of each segment of the filled tube opposite the movable blades to progressively take on a convex shape with progressive movement of the filled tube; and progressively cutting the filled tube into segments by causing the plurality of blades to move with the filled tube and progressively towards the movable support at an angle of about 2 to 30° and into the filled tube with movement of the filled tube through the cutting station, whereby the filling in any portion of the tube engaged by a blade is progressively pushed out of this portion prior to cutting when the blade engages the moving support. A process according to claim 1 further comprising coating the filled tube with ultra fine semolina prior to being cut. A process according to claim 1 or claim 2 in which the movable support comprises an endless support conveyor carrying a plurality of raised support plates spaced from each other along the endless support conveyor; the distance between the centre of one support plate and the centre of an adjacent support plate being substantially equal to the selected length of the filled dough products; the segments of the filled tube taking on a convex shape by sagging between adjacent support plates. A cutting apparatus for continuously cutting dough strands into segments, the apparatus comprising: an endless support conveyor (4) to transport the dough; and an endless cutting conveyor (6) positioned above the support conveyor (4) and carrying a plurality of blades (46) spaced from each other along the length of the cutting conveyor (6), the distance between adjacent blades (46) being equal to the desired length of the segments, and the cutting conveyor (6) being inclined downwardly in the direction of transport of the support conveyor (4) so that each blade (46) moves downwardly towards the support conveyor (4) with progressive movement along the cutting conveyor (6) to finally cuttingly engage the support conveyor (4). An apparatus according to claim 4 in which the cutting conveyor (6) is inclined downwardly at an angle in the range of 2 to 30° to the support conveyor (4). An apparatus according to claim 4 or claim 5 in which the support conveyor (4) carries a plurality of raised support plates (20) spaced from each other along the length of the support conveyor (4); the distance between the centre of one support plate (20) and the centre of an adjacent support plate (20) being substantially equal to the desired length of the segments. An apparatus according to claim 6 in which support plate (20) is raised at its centre and slopes concavely away to its leading (24) and trailing (30) edges. An apparatus according to any one of claims 4 to 7 in which the support plates (20) are in the form of elongate bars which extend transverse the support conveyor (4). An apparatus according to claim 8 in which the blades (46) each comprise an elongate bar which extends transverse of the cutting conveyor (6); the bar having a raised cutting edge (48) extending along its length. An apparatus according to any one of claims 4 to 8 in which the support conveyor (4) and the cutting conveyor (6) are each made up of a plurality of chains (8, 12) arranged in parallel; the support plates and the and blades being affixed to and extending across the chains.

Inventors: DAOUSE ALAIN, PLESSIER ALAIN, DAOUSE, ALAIN, PLESSIER, ALAIN
Applicants: NESTLE SA, SOCIETE DES PRODUITS NESTLE S.A.
Application year: 1994
Main classification: A21C9
IPC codes: A21C9, A47J43, A21C11